I think hyperbezier would be a natural fit for boat hulls, but it's not a mathematically precise approximation to elastica either. I'd say to carefully evaluate it, and I'd very much like to hear how that goes.
ETA: "parallel curve of elastica" is an intriguing curve family to consider for this application, as it has the correct number of parameters and ticks a lot of the other boxes. However, the math for this is hard mode.